STANBOL-811: The TopicClassificationEngine does no longer use File#tempFile(..) to create the folder for performing CVFold's. The root folder is now configured by the unit tests. Within OSGI the property is not set and would cause a NPE if no ManagedSolrServer is present (This should be reviewed by ogrisel); Minor: also added some loggings to the unit tests.

git-svn-id: https://svn.apache.org/repos/asf/stanbol/trunk@1450615 13f79535-47bb-0310-9956-ffa450edef68